10 results about "Pyridine synthesis" patented technology

The invention relates to a synthesis method of 3-chloro-2-hydrazinopyridine. According to the method, 2, 3-dichloropyridine and hydrazine hydrate are used as raw materials, potassium carbonate is used as alkali, and the 3-chloro-2-hydrazinopyridine is obtained at a high yield under the condition of a certain pressure. The method has the advantages that the dosage of hydrazine hydrate can be effectively reduced, the problem of excessive hydrazine hydrate in the synthesis process of 3-chloro-2-hydrazinopyridine is solved, and the method has the advantages of atom economy, simple and feasible process, convenience in three-waste treatment, high product yield and purity and the like, and is suitable for industrial production of 3-chloro-2-hydrazinopyridine.

The invention relates to a synthesis method of 4-(4-cyano-2-methoxyphenyl)-5-ethoxy-1, 4-dihydro-2, 8-dimethyl-1, 6-naphthyridine-3-formamide, which comprises the following four steps: carrying out a Knoevenagel condensation reaction, carrying out a Hantzsch dihydropyridine synthesis method, carrying out an O-ethylation reaction and carrying out a deprotection reaction to synthesize the 4-(4-cyano-2-methoxyphenyl)-5-ethoxy-1, 4-dihydro-2, 8-dimethyl-1, 6-naphthyridine-3-formamide, and carrying out a reaction to obtain the 4-(4-cyano-2-methoxyphenyl)-5-ethoxy-1, 4-dihydro-2, 8-dimethyl-1, 6-naphthyridine-3-formamide. The preparation method of the 4-(4-cyano-2-methoxyphenyl)-5-ethoxy-1, 4-dihydro-2, 8-dimethyl-1, 6-naphthyridine-3-formamide has the advantages that the selectivity is high, the post-treatment is simple, the yield and the purity of the product are high, a new synthesis route and method are developed for synthesizing the 4-(4-cyano-2-methoxyphenyl)-5-ethoxy-1, 4-dihydro-2, 8-dimethyl-1, 6-naphthyridine-3-formamide, the amplified production is conveniently realized, and the method is suitable for industrial production. The method has good application potential and research value.

The application discloses a preparation method of a catalyst for synthesizing pyridine from 3-methylpyridine and relates to the technical field of catalysts. The catalyst comprises the following steps: ZSM-5 is used as a carrier, V2O5, CoO and Ag are used as active components, molecular sieve ZSM-5, citric acid, ammonium metavanadate, cobalt nitrate, silver nitrate and deionized water are mixed, and then are filtered, dried and calcined to obtain a supported high-efficiency catalyst; the catalyst is filled in a fixed bed, 50% 3-methylpyridine is used as raw material, and a demethylation reaction is carried out under the action of high temperature, the catalyst and air to produce pyridine. The catalyst used in the application does not need to be frequently activated, the activation frequency is low, the catalyst stability is good, the catalyst is not prone to deactivation, can continue to operate stably after activation, catalyst loss is greatly reduced, 3-methylpyridine can be efficiently converted into pyridine by using the prepared catalyst, and the dilemma of waste caused by small demand for 3-methylpyridine in the market is solved.

The invention discloses a preparation method of a flaky ZSM-5 molecular sieve and application of the flaky ZSM-5 molecular sieve in pyridine synthesis reaction, and belongs to the technical field of molecular sieve preparation and catalytic application. Comprising the following steps: adding a silicon source, an aluminum source, a template agent and a regulator into all-silicon ZSM-5 molecular sieve crystallization mother liquor, and fully stirring to form gel; and carrying out dynamic crystallization on the gel, cooling, carrying out suction filtration on the product, washing to be neutral, drying to obtain flaky ZSM-5 molecular sieve raw powder, and roasting the raw powder to remove the template agent to obtain the flaky ZSM-5 molecular sieve. The molecular sieve is sprayed and then applied to a pyridine synthesis reaction through aldehyde ammonia condensation, and the pyridine yield and the catalyst stability can be remarkably improved. The ZSM-5 molecular sieve with a smaller particle size is synthesized by recycling the all-silicon ZSM-5 molecular sieve mother liquor, so that efficient cyclic utilization of resources is realized, the use amount of a template agent is reduced, the influence of waste discharge on the environment is reduced, the catalytic performance is excellent, and the method has important economic and environment-friendly values.

The application discloses a preparation method of a catalyst for synthesizing 1-methyl pyridine chloride, belongs to the technical field of catalyst synthesis, and utilizes the silica produced by the hydrolysis of tetraethyl orthosilicate under alkaline conditions to coat polypenyl sulfon, so as to obtain modified silica. The modified silica can further be chemically bonded with gamma-(2,3-epoxypropoxy) propyl trimethoxysilane, 1-aminopropyl-3-methyl imidazole tetrafluoroborate and hexamethylenetetramine, so as to obtain the catalyst for synthesizing 1-methyl pyridine chloride, and the synthesis conversion rate of 1-methyl pyridine chloride is improved.

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing 4-acetylpyridine from pyridine, which comprises the following steps: reacting pyridine serving as an initial raw material with acetic anhydride and iron powder to obtain an intermediate 4-ethylpyridine; and carrying out catalytic oxidation to obtain the target product 4-acetylpyridine. According to the method for preparing 4-acetylpyridine, the reaction steps are few, the raw material price is low, and the catalyst used in the oxidation reaction can be recycled, when 4-ethylpyridine is synthesized, after iron powder is added, the problems that in the heat preservation reaction stage, the fluidity of reaction liquid becomes poor, and a stirring paddle is locked are solved by adopting a xylene adding mode; water is removed before rectification, so that the problem of ternary azeotropy of water, pyridine and 4-ethylpyridine is solved; before the oxidation reaction, the conversion rate is obviously improved by vacuumizing oxygen replacement and adopting a micro-positive pressure reaction mode, and the catalyst N-hydroxyphthalimide can be recycled, so that the method has a relatively good application value.

The utility model belongs to the technical field of DCTF crude product treatment, and discloses a standing layering kettle for crude product treatment in the synthesis process of 2, 3-dichloro-5-trifluoromethylpyridine, which comprises a kettle body, one side of the top end of the kettle body is provided with a feeding pipeline, the bottom end of the kettle body is provided with a slag discharging port, one side of the bottom end of the kettle body is provided with a discharging port, and the other side of the bottom end of the kettle body is provided with a discharging port. A plurality of through holes are formed in the surfaces of the partition plates in a penetrating manner, a cover plate is mounted at the top end of the kettle body through a flange, a central rotating shaft is rotationally mounted at the bottom end of the cover plate through a bearing seat, a plurality of stirring plates are mounted on one side of the central rotating shaft, and the bottom end of each stirring plate clings to the top end of each partition plate. According to the device, a crude product can be layered in the kettle body, the standing time is shortened, uniform distribution of materials is ensured through the central rotating shaft, the stirring plate and the cover plate, the phenomena of precipitation and agglomeration are avoided, layering is more thorough, the production efficiency is further improved, and the stability of the layering kettle is improved.

The invention relates to the technical field of chemical synthesis, in particular to a 2-amino-4-trifluoromethyl-pyridine synthesis device and method.The 2-amino-4-trifluoromethyl-pyridine synthesis device comprises a reaction kettle and a stirring shaft, a plurality of first stirring blades are arranged on the stirring shaft in the circumferential direction, and a plurality of second stirring blades are movably installed on the first stirring blades; a plurality of sliding rods are arranged on the first stirring blade and the second stirring blade in a sliding mode, turbulent flow blades are rotationally arranged on the sliding rods, and mixing strengthening units connected with the turbulent flow blades are arranged on the first stirring blade and the second stirring blade and used for pushing out the turbulent flow blades in the initial stage of reactant mixing. When the 2-amino-4-trifluoromethyl-pyridine synthesis device and method are used, the efficiency and safety of a synthesis process are remarkably improved through cooperation of a dynamic turbulent flow structure and a boundary layer control structure, in the initial stage of reactant mixing, the small turbulent flow blades contained in the stirring blades are accurately pushed out, the turbulence degree of fluid is enhanced, and the efficiency of the synthesis process is improved. And rapid dispersion of a reactant solution is realized.

The invention discloses a nitrilase mutant and application thereof in synthesis of nicotinic acid, and belongs to the technical field of bioengineering. Comprising a nitrilase mutant of a new amino acid sequence formed by replacing one or two amino acid residues in 95 alanine and 124 asparagine of an original nitrilase BbNit amino acid sequence with other amino acid residues, a coding gene of the nitrilase mutant, and a recombinant expression vector and a recombinant expression transformant containing the coding gene sequence, the invention relates to a catalyst containing a recombinant nitrilase mutant and application of the catalyst to catalytic hydrolysis of 3-cyanopyridine to synthesize nicotinic acid. Compared with the prior art, the nitrilase mutant prepared by the invention has the advantages that the enzyme catalytic activity is improved, the tolerance to a substrate 3-cyanopyridine is also improved, and the problems of long reaction time, low space time yield and the like in synthesis of nicotinic acid by biologically catalyzing hydrolysis of 3-cyanopyridine are solved, so that the nitrilase mutant is beneficial to practical application in industrial preparation of nicotinic acid.